HOW TO PREVENT STRANGLES

Given the impact a strangles outbreak can have from a welfare and economical perspective, preventing the disease is a much more attractive scenario than having to deal with an outbreak. Biosecurity and vaccination are the two important aspects of prevention and they go hand-in-hand

Watch the video below to learn about preventative measures for controlling strangles:

• Quarantine new arrivals to a yard for a minimum of three weeks so that they have no direct with other horses, nor indirect contact via equipment used for other horses.
• Test horses using the Strangles blood test and guttural pouch endoscopy ideally before arrival or whilst in quarantine to identify horses exposed to S. equi.
• Do not allow your horse to share drinking water and avoid direct contact with other horses whilst attending equine events.
• Regularly clean and disinfect all food and water containers, clothing, stabling and equipment at your yard. • Clean and disinfect horseboxes/trailers before and after collecting any new horses.
• Wash hands between handling different horses.

Vaccination against strangles can:

• Reduce the severity of clinical symptoms.
• Reduce the number of abscesses and spread of the disease.
• Improve protection at individual horse level as well as on a yard level.
• Reduce the risk of horses contracting strangles whilst travelling to other premises or attending equine events.

Vaccination aims at maximizing herd immunity, which is achieved when a high proportion of a population is vaccinated. As a result it becomes difficult for a contagious agent to spread because there are not many animals left who can become infected and transmit the disease.

DIVA is short for: Differentiate Infected from Vaccinated Animals. Horses vaccinated with a DIVA vaccine can attend events and sales or move yards normally without triggering positive tests, unless they have been exposed to S. equi. Recently a new intramuscular strangles vaccines has become available that does not contain live or killed S. equi cells and instead targets the equine immune response to 8 important proteins to give the best protection. These proteins are different from the once leading to a positive response in diagnostic tests tests.

Young and old horses are at highest risk of severe disease if they become infected with S. equi. Vaccination protects these susceptible horses from potential introductions of S. equi. Vaccination is also highly recommended for: horses before competition, sales or possible exposure events and for horses in an area with known outbreaks of strangles. Vaccinating all horses on the farm raises herd immunity, and decreases the risk of spread of the disease.

There are some guidelines with respect to vaccination in an outbreak or high-risk situation:

• Horses with clinical signs and those in contact should not be vaccinated
• Vaccinated horses that have not been in contact with cases:
• Last dose >2 months: booster doses will maximise immunity
• Last dose <2 months: no booster required
• Unvaccinated horses: start primary course: partial protection from 2 weeks after 2nd dos

This will depend on the biosecurity policy of the yard and whether the horse has also been vaccinated against other equine infectious diseases klike influenza and equine herpes disease. With respect to strangles however, if the horse has been vaccinated, there is no reason for quarantine anymore.

This will depend on the type of vaccine being used. If a vaccine with DIVA capability has been used, then the horse will not test positive, unless it has been infected with S. equi previously.

It is generally recommended not to exercise horses in the 2 to 3 days following vaccination. This depends on whether the horse shows a rise in body temperature as a reaction to vaccination or not. Temporary fever after vaccination is not uncommon as this is part of the immune system activation.